Fatty alcohol alkoxylate

ABSTRACT

A compound of the formula ##STR1## where R, which may be the same or different, is selected from at least one of hydrogen, methyl, ethyl and phenyl, at least one R on each --OCHR--CHR-- unit being hydrogen; where m is an integer selected from 1-100; where n is an integer selected from 8 and 9. The preferred process of preparation is by the reaction of alkylene oxide with linoleyl alcohol in the presence of a catalyst which is a Bronsted base. 
     The compounds are useful as reactive surfactants in aqueous emulsion polymerisation processes.

This invention relates to alkoxylates of unsaturated fatty alcohols andto their use in surface coating compositions.

It has been known for some time that it is possible to prepare moleculeswhich consist of a hydrocarbon chain and an oxyalkylene chain (usuallyan oxyethylene chain), and such compounds have been useful, for example,as surfactants in a variety of end uses, one typical example beingsurface coatings. The hydrocarbon chain may be derived from a long chainfatty alcohol, a very common example being oleyl alcohol. This alcoholhas a single double bond but this double bond is very unreactive undernormal polymerisation conditions and oleyl ethoxylates have enjoyed wideuse in many fields where the presence of this unsaturation is of noconsequence.

In those cases where, in that part of the hydrocarbon alkoxylate whichis lipophilic, there is desired the presence of unsaturation which isrelatively reactive with respect to an addition polymerisation reaction,special compounds have been devised. Thus, while compounds such as oleylethoxylate will work in the multi-polymer particle dispersions disclosedin U.S. Pat. No. 4,413,073, the preferred unsaturated surfactantsdescribed in this disclosure are more reactive and the most preferredsurfactants have multiple double bonds derived from such molecules aspentaerythritol triallyl ether. Similarly, in European PublishedApplication 0 002 252, the applicants use allylic bonds for reactionwith the fatty acid chains of the water-borne alkyd resin which isdescribed in that document.

It has now been found that it is possible to provide an unsaturatedfatty alcohol alkoxylate whose unsaturation is usefully reactive. Thereis therefore provided, according to the present invention, a compound ofthe formula I ##STR2## where R, which may be the same or different, isselected from at least one of hydrogen, methyl, ethyl and phenyl, atleast one R on each --OCHR--CHR-- unit being hydrogen; where m is aninteger selected from 1-100; where n is an integer selected from 8 and9.

The oxyalkylene chain of the compound is of 2-101 and preferably 6-50units in length. The nature of the individual units is very muchdetermined by the end use to which the compound will be put. Forexample, if the compound is to be a reactive surfactant in an aqueousemulsion system, the oxyalkylene chain will consist mainly, andpreferably solely, of oxyethylene units. Provided that the desiredbalance between the lipophilic and hydrophilic portions of thesurfactant can be achieved, it is possible to include a proportion ofoxypropylene, oxyethylethylene or oxyphenylethylene units. These areadvantageously located on the chain adjacent to the lipophilic portionas they increase the overall lipophilicity of the molecule. Thepreferred oxyalkylene unit is the oxyethylene unit; those compoundsaccording to the invention which comprise oxyalkylene units other thanoxyethylene units are useful as intermediates for other products, butthe oxyethylene unit is the most useful and preferably all of theoxyalkylene units are oxyethylene units.

It is particularly preferred that the double bonds in the compounds ofthe invention exhibit opposite geometrical isomerism, that is, one istrans and the other cis, not both cis or trans.

Accordingly we provide in a particularly preferred embodiment of theinvention a compound of formula I as hereinbefore described in which thedouble bonds exhibit opposite geometrical isomerism.

The compounds of this invention may be synthesised by any convenientmeans. A particularly valuable method of preparing the preferredcompounds forms part of this invention. There is therefore provided amethod of preparing a compound according to the invention comprising thereaction of alkylene oxide with linoleyl alcohol in the presence of abase catalyst which is a Bronsted base.

It will readily be appreciated that the structure of this alcohol isdifferent to that of the non-oxyalkylene chain part of the compounds;linoleyl alcohol is cis-9, cis-12-octadecadienol. It has been foundthat, under the conditions of the alkoxylation, one of the double bondspositioned at the 9- or the 12-position moves into a conjugatedarrangement with respect to the other, and at the same time this bondchanges its stereochemical configuration such that there is one cis-bondand one trans-bond.

The linoleyl alcohol for use in this aspect of the invention may be apure substance. Alternatively, it is possible to use one of thecommercially-available mixtures of fatty alcohols which contain asignificant proportion of linoleyl alcohol. It has been found that thealkoxylation of such mixtures can give a product which is acceptable formany uses and which is considerably cheaper than the alkoxylated purealcohol. However, it is essential that at least 15% and preferably atleast 40% by weight of the mixture be linoleyl alcohol. Examples ofsuitable commercially-available mixtures can be found in the "Ocenol"range of product of Henkel KGaA, one suitable one being the "110-130"grade.

The invention also, therefore, provides a chemical composition which isessentially a blend of alkoxylated fatty alcohols, at least 15%(preferably at least 40%) by weight of which are compounds of formulaI--as hereinabove described.

By "Bronsted base" is meant a base which is capable of abstracting aproton. While any Bronsted base will work to some extent in theinvention, it will readily be appreciated by the skilled worker that,for some bases, the obtaining of acceptable yields will requireunacceptably long reaction times and/or unacceptably severe reactionconditions, and the use of such bases is not therefore a practicalproposition. As a general rule, reaction times should be no longer than48 hours and reaction conditions no more severe than 160° C. temperatureand 1000 kPa pressure. Any Bronsted base which gives an acceptable yieldunder conditions such as these is especially preferred for use in thisinvention. Examples of preferred bases are the alkali metal and alkalineearth metal alkoxides and hydroxides, particularly sodium methoxide andpotassium hydroxide. Other suitable bases include metal hydrides, suchas sodium hydride.

The compounds of this invention are useful in a number of applications,but compounds with appropriate HLB values are especially useful asreactive surfactants in the formulation of aqueous dispersions for usein water-borne coating compositions. They are, for example, useful inthe preparation of polymer particles.

In a further embodiment of the invention we therefore provide a processfor preparation of polymer particles, the process comprisingpolymerising in aqueous media unsaturated monomer in the presence of atleast one compound of formula I as hereinbefore described.

The nature of the unsaturated monomer is not narrowly critical andparticles may be prepared by this process using a wide range of monomerscommonly used in suspension and emulsion polymerisation, for example oneor more of the monomers selected from the group of the C₁ -C₁₂(preferably the C₁ -C₄) alkyl acrylates and methacrylates, (meth)allylacrylates and methacrylates, glycidyl methacrylate and vinyl acetate,hydroxy, butyl acrylate, 2-ethoxy ethyl acrylate, glycidyl acrylate,methyl methacrylate, ethyl methacrylate, butyl methacrylate, stearylmethacrylate, methacrylic acid, methoxy propyl methacrylate, cyclohexylmethacrylate, benzyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, N-butoxymethylmethacrylamine, N-butoxymethyl acrylamide, glycidyl methacrylate, vinylacetate, vinyl propionate, styrene, 1-methyl styrene, vinyl toluene,methoxy styrene and vinyl pyridine, di-butyl maleate and vinyl chloride.

The known techniques of suspension and emulsion polymerisation,including the selection of appropriate polymerisation initiators, areapplicable to the preparation of the aqueous dispersion of ourinvention. As is understood in the art polar monomers may need to beused in combination with less polar monomers to achieve the appropriateaqueous dispersion. Either thermally-activated or redox Initiators maybe used.

Due to the reactivity of the compounds of formula I they have been foundto provide a particularly stable dispersion of polymer particlestherefore providing a significant improvement in aqueous coatingcompositions. In such applications, the compounds of formula I may beused alone or in combination with other surfactants, for example anionicsurfactant. We therefore further provide an aqueous dispersion ofpolymer particles stabilized by at least one compound of formula Iaccording to any one of claims 1 to 5.

The aqueous dispersion may comprise additives which adapt it for use asa coating composition.

Coating compositions may be prepared by blending standard additives suchas pigments, extenders, antifoams, thickeners and fungicides into thedispersion in art-recognized quantities using known methods.

An example of polymer particles which may be produced using thecompounds of formula I is described in U.S. Pat. No. 4,413,073.

A further particularly preferred example of polymer particles which maybe prepared using compounds of formula I are core-sheath particles ofthe type described in Australian Patent Application No. 52006/90. Suchparticles will have diameters of less than 100 nm and comprise a core ofpolymer of an ethylenically unsaturated monomer and a sheath comprisingpolyoxyalkylene chains wherein said polyoxyalkylene chains are derivedfrom the covalent bonding of compounds of formula I with the coreaddition-polymer.

The invention is further described with reference to the followingexample in which all parts are expressed by weight.

EXAMPLE I

Preparation of compounds according to the invention, the compoundshaving 12 moles ethylene oxide per mole of unsaturated chain.

49.6 parts of linoleyl alcohol (cis-9-cis-12-octadien-1-ol; 994 exSigma) was dissolved in 250 parts xylene containing 0.03 parts each ofphenothiazine and 4-methoxyphenol. 1.8 parts 30% sodium methoxide inmethanol was then rapidly added to the stirred solution which was thentransferred to a clean dry stainless steel autoclave at 35° C. underslight vacuum. A further 50 parts xylene was used to rinse the residuesfrom the flask and the line. The reactor was twice evacuated and purgedwith nitrogen, then heated under vacuum to 70° C., at which point xylenebegan to distil over. The autoclave was evacuated and purged withnitrogen once more, and was then pressurised to 70 kPa and heated to140° C. Ethylene oxide (98 parts) was charged batchwise over 2 h,keeping the temperature below 143° C. and the pressure below 400 kPa.The reaction mixture was allowed to react out at 142°±2° C. over 1 1/2h, cooled to 55° C., evacuated and purged and discharged into a solutionof 0.84 parts of orthophosphoric acid in 5 parts water. Volatiles wereremoved under vacuum (rotary evaporator followed by oil pump at 0.5-1 mmHg) at 70° C. The product, a pale yellow oil was filtered through"Celite" whilst warm. The cloud point (10% w/w in water) was 77°-77.5°C. Carbon-13 NMR showed that the linolenyl alcohol double bond peaks(127.95, 128.02, 130.12, 130.20 ppm from tetramethylsilane (TMS)) haddisappeared, to be replaced by peaks due to the cis-9-trans-11 andtrans-10-cis-12 isomers in approximately equal proportions (125.60,128.59/128.62, 129.93/129.99, 134.59 ppm from TMS).

EXAMPLE 2

Preparation of compounds according to the invention from acommercially-available alcohol mixture, the compounds having 10 molesethylene oxide per mole of unsaturated chain.

616 parts of "Ocenol" (Trade Mark) 110-130 (ex Henkel KGaA), (acommercially available mixture of fatty alcohols being approximately 40%by weight linoleyl alcohol) was warmed to dissolve any separatedcomponents. It was then charged to an autoclave and purged withnitrogen. There was then slowly added 18 parts of 30% sodium methoxide.The vessel containing the sodium methoxide was rinsed three times with15 parts ethanol and this ethanol slowly charged with stirring. Theautoclave was evacuated, purged with nitrogen and then evacuated andheated to 130° C., all volatile materials being stripped off. Theevacuation and purging with nitrogen was repeated and 1034 partsethylene oxide was then added over a period of 2 hours, the autoclavebeing maintained at 130°-145° C. and 100-500 kPa pressure. Reaction wascontinued for 30 minutes, and the contents of the autoclave were thencooled and volatiles were stripped off under vacuum. The cloud point ofa 10% w/w mixture with water was found to be 71.5° C.-72.5° C. The pH ofthe product was reduced to 5.5 by the addition of an 85% solution oforthophosphoric acid in distilled water (9 parts was needed). Theproduct was finally stripped under vacuum at 115° C. for 3 hours andfiltered while hot through "Celite".

The final component was a pale orange-yellow solid. NMR analysis showedthat the 9,12-arrangement of the double bonds of the linoleyl alcoholhad changed to a mixture of 9,11- and 10,12-arrangements, to givecompounds according to the invention.

EXAMPLE 3

Preparation of compounds according to the invention, the compoundshaving the approximate composition I mole unsaturated chain to 40 molesethylene oxide.

The compound was made in an analogous manner to example 2, with 185parts "Ocenol" 110-130 and 1215 parts ethylene oxide. The product was anoff-white solid which NMR analysis showed to consist mainly of a mixtureof oleyl, 9,11- and 10,12-double bond-containing compounds.

EXAMPLE 4

Preparation of compounds according to the invention using two alkyleneoxides (in this case propylene and ethylene oxides in the approximateunsaturated chain: propylene oxide:ethylene oxide mole ratio of 1:4:10).

"Ocenol" 110-130 (449 parts) was charged into a clean, dry autoclave at50° C. and evacuated and purged with nitrogen. 18.0 parts 30% sodiummethoxide in methanol, followed by 3×20 ml. rinse methanol was thencharged to the autoclave with stirring. The reactor was evacuated andpurged and then heated to 120° C. under vacuum. Propylene oxide (400parts) was added over 2 h at 130°-135° C. and 100-200 kPa pressure. Thereaction contents were reacted out for 1 1/2 h and the reactor was thenevacuated and purged to remove any residual propylene oxide. Ethyleneoxide (753 parts) was then added over 1.2 h, reacted out for 1 h, cooledto 75° C., stripped under vacuum and neutralised with 10.4 parts 85%phosphoric acid in 60 ml water. The product, a pale orange-yellowliquid, was dehydrated under vacuum to 120° C. for 3 h and filteredwhile hot through "Celite". The cloud point of a 10% w/w solution was55.5°-56.5° C. NMR analysis confirmed the alteration of the9,12-unsaturated double bond arrangement into a mixture of 9,11- and10,12-arrangements.

EXAMPLE 5

The use of a compound according to the present invention in thepreparation of an aqueous dispersion of addition polymer particles.

The materials and quantities used were as follows:

    ______________________________________                                        Stage                                                                         ______________________________________                                        A         deionised water  106.74  parts                                                "Fenopon" (trade mark)                                                                         3.30                                                         CO 436 surfactant                                                             30% HCl          3       drops                                                1% ferrous sulphate                                                                            4.18                                                         solution                                                            B         t-butyl perbenzoate                                                                            0.18                                               C         methyl methacrylate                                                                            113.37                                                       butyl acrylate   97.77                                                        methacrylic acid 3.00                                                         compound from Example 2                                                                        15.62                                              D         deionised water  143.81                                                       sodium erythorbate                                                                             10.49                                                        (10% aqueous solution)                                              E         t-butyl perbenzoate                                                                            1.54                                               ______________________________________                                    

The stage A materials were added to a reaction vessel (the hydrochloricacid being sufficient to reduce the pH of the mixture to about 2) andwere stirred under nitrogen for about 20 minutes.

The stage C monomers were mixed in another vessel and the Example 2compound melted and added to them. The stage D materials were then addedto the stage C materials and the resultant mixture was mixed vigorouslyto form a coarse emulsion.

The tert-butyl perbenzoate of stage B was added to the stage A materialsin the reaction vessel and stirring was continued for 10 minutes toemulsify it. 10% of the stage C+ stage D mixture was then added andstirred in, stirring was stopped and the mixture allowed to exotherm,cooling being applied to keep the temperature below 30° C.

After 30 minutes, the stage E tert-butyl perbenzoate was added to thereaction vessel with stirring and the remainder of the stage C+ stage Dmaterials fed in over a period of 80 minutes, maintaining thetemperature at 30° C. When addition was complete, stirring and coolingwere continued for a further 60 minutes. After cooling to 20° C.,ammonium hydroxide solution was added to raise the pH to 8.5.

The resulting product was a fine particle size (83 nm average diametermeasured using a "Nanosizer") aqueous dispersion of 46.0% solidscontents.

The claims defining the invention are as follows:

I claim:
 1. A compound of the formula I ##STR3## where R, which may bethe same or different, is selected from hydrogen, methyl, ethyl orphenyl, at least one R on each --OCHR--CHR-- unit being hydrogen; wherem is an integer selected from 1-100; where n is an integer selected from8 and
 9. 2. A compound according to claim 1 wherein the double bondsexhibit opposite geometrical isomerism.
 3. A compound according to claim1, wherein m is an integer selected from 6-50.
 4. A compound accordingto claim 1, wherein most of the groups R are hydrogen.
 5. A compoundaccording to claim 4, wherein all of the groups R are hydrogen.
 6. Aprocess of the preparation of a compound according to claim 1 comprisingthe reaction of alkylene oxide with linoleyl alcohol in the presence ofa catalyst which is a Bronsted base, wherein the maximum processtemperature is 160° C.
 7. A process according to claim 6, wherein theBronsted base is one which will give a yield within the followingparameters;(a) a reaction time of 48 hours maximum; (b) a temperature of160° C. maximum; and (c) a pressure of 1000 kPa maximum.
 8. A processaccording to claim 6 or claim 7, wherein the Bronsted base is selectedfrom alkali or alkaline earth metal hydroxides or alkoxides or metalhydrides.
 9. A process according to claim 8, wherein the Bronsted baseis selected from sodium methoxide, potassium hydroxide or sodiumhydride.
 10. A process according to claim 6, wherein the linoleylalcohol comprises part of a fatty alcohol mixture having a linoleylalcohol content of at least 15% by weight.
 11. A process according toclaim 10, wherein the linoleyl alcohol is at least 40% by weight.
 12. Achemical composition which is essentially a blend of alkoxylated fattyalcohols, at least 15% by weight of which alcohols are compoundsaccording to claim
 1. 13. A chemical composition which is essentially ablend of alkoxylated fatty alcohols, at least 40% by weight of whichalcohols are compounds according to claim 1.